Casting vs Blueprint Interface: When should I use each one? - With Interactive Door Examples

This episode answers the common question, "When do I use casting to communicate between blueprints, and when do I use a blueprint interface?"
Also a quick tutorial on how to make a door open and close properly via Timeline and an overlap collision box.
0:00 Quick answer
0:58 Setting up the door via a Timeline
3:42 Casting
6:07 Blueprint interfaces

[@DoctorMGL]

casting render the entire blueprint before you can use it, in case of large blueprints casting them will consume more which is bad for your game optimization in other hand, interfaces allow you to call only certain parts you specify, which is great for performance

[@truespiritualmeditation]

Good to know... Seems that casting is inefficient as code also, look like you would create a lot of repeated code using casting?

[@Yggdrasil777]

Very nice explanation with a good example for casting and interface.

[@GeneralNovais]

The problem with CAST TO is that, even when the objects are not interacting, Unreal loads the object into memory together. For example, if you have a CAST TO door on your character, your character will be loaded into memory and the door's BP will also be loaded into memory, even if you are never interacting with it.

[@chrum91]

This is a fantastic example of interfacing. Would you use interfaces to grab information from other blueprints or casting?

[@NumenBrothers]

You can do either one- again it comes down to, do you know the specific actor in which you are communicating? If not, use an interface, and pass that specific information through the interface via Inputs (variables on the interface) and then implement the interface (as event) on any/all possible receiving actors

[@TheSebledingue]

Thank you very much

[@truespiritualmeditation]

As a programmer in PHP and a few others it seems to me that an interface would be similar to building a function? To express this in hybrid way, for example... lets say you made a survival type game and there were 100 different items you can pick up. Weapons, food, wood, rocks, plants etc etc. INTERFACES seems to me like... If it were possible to write a game in PHP, I would create a function (one block of code) and send to that block the variable values it needs, and then ask that code to detect and reference each object and then use an array, to store all the values for each object..... Which would be way more efficient.... But CASTING seems like I would have to write a block of code for each of the 100 possible objects?.... Am I understanding this correctly?

[@NumenBrothers]

Yes correct!

[@truespiritualmeditation]

Wrote this before watching the rest of the video... you basically say that LOL. Thanks. @@NumenBrothers

[@user-ch3jv5pk4o]

I have a nice lesson for you too: press Ctrl-Shift-W, set scale to 1.4-1.5 and your videos instantly become useful even in resolutions lower than 4K.

[@MaxStudioCG2023]

hey man how did you learned all those unreal codes? and not reffering to this doors :)) ...i have 1 and hafe year learning and i still watching tutorials to make stuff :l i dont know if this is the learning process taking so long or is just me stupid haha :)))) ...i mean i do stuff (like als some fight things posted some on my youtube ) but yea watching videos and folowing tuts.... :D

[@NumenBrothers]

It's like learning a language. How long did it take you to learn your first language? How did you do it? You don't even realize it as you're doing it, but your mind is building a map from the ground up, such that you get to a point where it's like riding a bike- your mind is automatically trained to reach for the right word, the right phrase, or the right function to implement into reality that which was just a figment of your imagination a moment before. I recommend starting with disciplining yourself- a minimum of 1 hour a day of game dev, and just keep going. Because you will get to the point where it starts to flow naturally, and if that happens, most likely you will love it. But also sometimes the best approach is to move sideways- completely counterintuitively. Perhaps a topic that has nothing to do with game dev, which you can then marry to your creative efforts in game dev. I suspect the most successful game developers will have loves that fall well outside the realm of game dev that they can bring to the game dev arena to bring forth completely original forms and ideas in the arena of the game.

[@MaxStudioCG2023]

@@NumenBrothers haha thanks for the anser ....i do like all day of UE5 dev ..ofcource stuff in real life also but most of time on game dev lately :)))) ...haha and speaking of languages i learned my firs language (spanish) in like hafe year spoke and whriten ,english toke me longer haha :D ......but game dev definetly will take longer :))) (for example in my project i want to make a new skill like something where character flash true his target multiple times from side to side and each time dealing damage like a super skill i dont event know where to start :))))) searching for tutorials that dont exist (i saw some trailers where people used 1 or 2 animations for that basicaly needing some calculation to place the player from 1 side to other side and spawn it few times with some flash dissapear and like leaving a trail behind reappearing the other side and so on :D ....but yea keep searching :)) ...and yes you right is like riding a bike but this bike is like a spaceshipp ... :D

[@NumenBrothers]

the best guy I know for learning Niagara is @Tharlevfx

[@MaxStudioCG2023]

@@NumenBrothers thanks but i dont think i need niagara ...more like the coding part (for effects i have enough niagara and other effects)

[@user-ch3jv5pk4o]

@@NumenBrothers @Tharlevfx knows Niagara pretty well but unfortunately his teaching skills lower than zero.

[@user-gg4lt6ym1p]

do u have paid courses?

[@NumenBrothers]

nope- this is something I do for fun